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In a previous blogpost I discussed how the Swiss scholar Conrad Gessner (1516-1565) describes two strange species of fish, which generate spontaneously. Previously I identified these species as the sprat and the Baltic herring. In this blogpost I explore the background of Gessner’s assumptions about the spontaneous generation of fish.

‘The aphya phalerica is mentioned by Aristotle, and it is confirmed the membras comes from this. I believe that the aphya phalerica generates spontaneously’

This tells us that the author believes these fishes to generate spontaneously, which seems somewhat surprising. The study of fish was a booming topic in Gessner’s day, from around 1550 renowned scholars produced one publication on fish after the other. All of these experts agreed that fish reproduce sexually. In fact, Gessner described this reproduction process in detail. He makes an exception however, for these two as well as a handful of other species. Why does he do this?

A belief in spontaneous generation, the coming into existence of living beings not from parents but through some other means, originates in the classical era and was still widely accepted within the scholarly community in the sixteenth century. Small creatures, such as for example insects, were thought to generate spontaneously. Some base material was needed for this, often dirt, mud, or decaying matter. From this material a living creature would form spontaneously. As Gessner indicates in his descriptions, we can trace such ideas back to Aristotle’s History of Animals. Aristotle combined information obtained from a variety of sources, resulting in an overview of ideas commonly accepted in the classical era. One such idea was spontaneous generation. While, like Gessner, Aristotle acknowledges that most fish reproduce sexually, he believed that some were the result of spontaneous generation.

Discussing fish, in book VI, part 15, of his History of Animals, Aristotle states:

“Such fish as are neither oviparous nor viviparous arise all from one of two sources, from mud, or from sand and from decayed matter that rises thence as scum”

Aristotle’s ideas were absorbed into Mediaeval, and later into Renaissance science. The idea that animals sometimes generated spontaneously remained more or less unchallenged, and often even seemed to be confirmed by experience. For example, a century after Gessner published his work, the Dutch artist Johannes Goedaert (1617-1668) left out a cup of his own urine and watched it over a period of time. Eventually flies emerged from the cup and, not having noticed the fly that must have laid its eggs near this rich source of nutrients, he took this to prove spontaneous generation. Goedaert would later change his mind but for a while found this experiment quite convincing. Similarly, a little before Goedaert conducted his experiment, Jan Baptist van Helmont (1580-1644) felt confident to provide the following recipe for mice: Place a dirty shirt or some rags in an open pot or barrel containing a few grains of wheat or some wheat bran, and in 21 days, mice will appear.

This illustrates perfectly why the concept of spontaneous generation proved so durable, our own observations often seem to confirm it. We can conclude from Aristotle’s History of Animals that the same sort of confusing experience appeared to confirm the concept in antiquity. Aristotle backs up his claim that certain fish can generate spontaneously by citing observations that others have shared with him.

“As a proof that these fish occasionally come out of the ground we have the fact that in cold weather they are not caught, and that they are caught in warm weather, obviously coming up out of the ground to catch the heat; also when the fishermen use dredges and the ground is craped up fairly often, the fishes appear in larger numbers.”

Aristotle imagined the spontaneous generation of such fish as a sort of chain. According to him, while very small fishes generate from foam that floats on the sea, larger fishes generate from the remains of the deceased smaller fish. A list is provided.

“From the aphya phalerica comes the membras, from the membras the trichis,[and] from the trichis the trichias.”

When the aphya phalerica dies, the membras generates from its decaying matter, when the membras dies the trichis generates from its remains, followed in due course by the trichias. As we can see, Gessner’s membras and aphya phalerica are mentioned here. This also explains why Gessner describes the former as springing from the latter. The aphya phalerica is the first stage in this chain of spontaneously generating fishes.

In Gessner’s day, Aristotle, as the founding father of natural history, was considered a much esteemed source of information. For this reason, Gessner and his contemporaries heavily relied on the information provided by him. Is this then a full explanation why Gessner believes these two fishes to generate spontaneously? It seems that Gessner was familiar with current catch records and market prices of the sprat, suggesting he had an informant who may have observed these species first hand. Surely someone like this, well-informed and possibly in possession of first-hand information, would know that the sprat springs from sexual generation as all other fishes do?

According to Aristotle this does not matter. He writes:

“the great majority of fish then, as has been stated, proceed from eggs. However, there are some fish that proceed from mud and sand, even of those kinds that proceed also from the pairing and the egg.”

Consequently, just because you have observed that a species sometimes comes from sexual generation, this does not mean they cannot also come from spontaneous generation. It really is quite hard to argue with that.

To Be Continued…

Is this all that is to be said on the aphya phalerica and the membras? Not quite. Closer inspection reveals that Gessner and Aristotle are not describing the same species. Where to Gessner an aphya phalerica is a sprat and a membras is a Baltic herring, to Aristotle the aphya phalerica was the anchovies and the membras something undefined, a large anchovies or another small fish. In a future blogpost we will explore this linguistic confusion.

In 1553 the French naturalist Pierre Belon published, in his book on aquatic animals De Aquatilibus, the here shown depiction of what at first glance appears to be a frightening sea-monster. Belon’s discussion of this animal is serious and detailed. This animal catches it’s prey by leaping up from the water, he writes, and he advises his readers not to eat it. It has a foul taste and smell, he explains, and can upset the stomach.

Pierre Belon. De aquatilibus. Paris, Charles Estienne, 1553. Library of the United States Department of Agriculture, Cambridge (Mass.).

What Belon fails to mention, and most likely did not know, is that this animal is in fact a European eagle ray which has been cut and twisted before being dried, in order to make it look like a monster. The distorted snout and twisted body are sure sights of human interference, and in fact such distorted rays were created on a large scale across Europe at this time. In the sixteenth century monsters were very much ‘in fashion’, and this widespread interest made it a lucrative business to create objects that could reasonably pass as monstrous creatures.

Five years later, in 1558, the less gullible Conrad Gessner included such a creation in his Historiae Animaliumand explained to his readers exactly how these were made. “Apothecaries and others”, he writes, “let the body of the ray dry and twist the skeleton, making the animal look like a winged serpent or a dragon. They bend the body and alter the shape of the head and mouth, and cut other parts off. The back and bottom part of the animal is tampered with and turned upright, making the animal look like it has wings”

Gessner admits that he also initially did not know the animal was a fake. The depiction was sent to him by an apothecary, who did not disclose this. Eventually however, he figured it out, and he strongly disapproved of the practice. He explains that he discloses how these creatures are made in order to warn his readers about these fakes, and about the fraudulent people who exhibit them and charge others money to see them. This needs to be explained, he writes, as “ordinary people are very much impressed with these things”.

Part of Gessner’s description of the dried ray. SUB Göttingen HSD

Rays and skates are in fact extremely suitable to make creations such as these. These fish already have a suggestive appearance, their underside looks to us as if we see a semi-human face, the nostrils looking like a pair of eyes. In addition, they can be easily manipulated, by curling the side fins over the back, twisting the tail into strange positions, and using string tied behind the head to create a neck. Finally, rays and skates can be easily dried in the sun, and shrink when this is done, resulting in an even more twisted and monstrous appearance.

In 1613 Gessner’s acquaintance and correspondent Ulysse Aldrovandi published a range of depictions of such monstrous dried rays, or jenny hanivers as they are nowadays called, in his De piscibus. The origin of the term jenny haniver may lie in the French phrase jeune d’Anvers, Antwerp having been a centre of production for these things.

An ardent collector of all sorts of naturalia Aldrovandi may well have seen and handled all the jenny hanivers he included in his book. It is known he owned several of them. The here shown depictions shows one which resembles a flying dragon which looks like it is mid-flight. Much like Gessner, Aldrovandi clearly indicates that such creatures are not real.

So does this mean that once the word was out naturalists were more sceptical about reports they received about strange creatures from the sea? Perhaps that is an overstatement. In spite of his critical description of the above shown specimen, Gessner also shows Belon’s jenny haniver in his Historiae Animalium and copies Belon’s description of it almost word for word, without any of the criticism voiced in his description of the other jenny haniver. One possible explanation for this is that it mattered to Gessner whether or not information came from what he perceived as a reliable source. An esteemed naturalist such as Pierre Belon was certainly that.

On top of this, just because something seems unlikely does not necessarily mean it isn’t true. As Gessner writes referring to other monstrous creatures, such as the sea-monk and the sea-satyr: some creatures have been reported either so often or by such reliable sources that he cannot exclude the possibility that they exist.

In his 1563 Fischbuch the Swiss scholar Conrad Gessner (1516-1565) describes a species of fish so oily that fishermen use it to burn their lamps. A puzzling statement… with the possible exception of whales, which were considered fish, most fish do not make for good fuel.

However, the description gets even stranger. On the next page Gessner describes another species which he claims ‘develops from the first’. At first glance it is unclear what he means by this. From the text it is fairly evident he doesn’t mean the first fish is a young specimen of the second, they really are two different species. And as if all this wasn’t strange enough, Gessner then points out that, like the first species that can be used to burn lamps, this second also has a peculiar use. It can be used to catch wasps.

Gessner calls the first fish schmelzling, a telling name that suits the anecdote about the fishermen. In German, schmelzling is related to the word schmelzen, melting in English. A schmelzler is a melter, something that melts. Since Gessner describes the fish as extremely oily, I can image what he means. He adds to this that this fish tends to fall apart in your hands.

The second fish is called membras. Like schmelzling this is not a name that immediately rings a bell. Consequently, it’s unclear which species Gessner was writing about. In my research I often come across descriptions such as these, which are at first glance so strange they present a set of puzzling questions. In these cases it usually helps to first determine which species the author was talking about.

Juveniles and geriatrics
Since I know Gessner claims the membras develops from the schmelzling, I could ask myself if perhaps the latter is a young and the former an adult specimen of the same species. It was not unusual around this time to call a fish by different names at different stages in its life. Juvenile fish can look quite different from their adult counterparts. However, Gessner makes it clear to his readers when he is talking about young specimens. For example, when describing young salmon, he describes this as junge Salm (young salmon). He does not do this here.

Looking at fins
In cases like this I look at the illustrations for confirmation. In this particular case these immediately show that these species may be similar but they are not the same. Fish are quite easy to tell apart by looking at certain physical characteristics, such as the position of the fins and the length-width ratio of the body. In this case, the fins provide sufficient information. The dorsal fin of the membras is implanted further forward than the beginning of the pelvic fin, while the dorsal fin of the schmelzling is implanted further back than the pelvic fin. In addition the membras has a very distinctively shaped snout.

So, what is a schmelzling?
So which two species are these? It is now time to look more closely at Gessner’s description of these fish. He writes that the schmelzling is a small species, with a row of sharp scales on its belly. The latter remark suggests this is a member of the herring family, as this is a very distinct characteristic of this group of fishes. As mentioned Gessner remarks that this fish is so oily it falls apart in your hands. He writes that when they encounter fishing fleets a layer of oil forms on the water surface. This oil, he states, is collected by fishermen, who use it for their lamps:

Although this seems a bit far-fetched, I can now figure out which species he is talking about. The schmelzling may be the sprat (Sprattus sprattus), which belongs to the herring family and is one of the oiliest fishes in existence. If I now look at the illustration again, I can confirm this. The position of the pelvic fin and overall appearance of the fish corresponds with what a sprat looks like.
Image: ifremer.fr (top) & Conrad Gessner’s Fischbuch, SUB Göttingen (bottom)

And how about the membras?
About the membras Gessner writes that this is a small herring-like fish. The fact that he places it in the herring family provides a clue. In his description of the herring Gessner refers to two small species that are common in the Baltic Sea. The sprat is extremely common in the Baltic Sea, as is a bigger ‘herring-like’ species, the Baltic herring (Clupea harengus membras). Could the membras then be the Baltic herring?

Again I can turn to the illustration for confirmation. The depiction of the membras displays features that are typical of the Baltic herring, such as a long, angular snout, and pelvic fins that are positioned further back on the body than the origin of the dorsal fin.

Sophia Hendrikx and Fishtories, 2016. Unauthorised use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Sophia Hendrikx and Fishtories with appropriate and specific direction to the original content.